The Canadian tar sands have been called the “most environmentally destructive project on earth”, with good reason. Extracting tar sands bitumen from under the boreal forests of Alberta, Canada requires huge amounts of energy and water. It has cleared vast tracts of forest, left scars on the land that are visible from space and threatened the health and livelihoods of indigenous First Nations communities across the region.

It is a well established fact that full exploitation of the tar sands is a grave threat to the climate. Emissions from tar sands extraction and upgrading are between 3.2 and 4.5 times higher than the equivalent emissions from conventional oil produced in North America.On a lifecycle basis, the average gallon of tar sands bitumen derived fuel has between 14 and 37 percent more greenhouse gas emissions than the average gallon of fuel from conventional oil.

But as bad as these impacts already are, existing analyses of the impacts of tar sands fail to account for a byproduct of the process that is a major source of climate change causing carbon emissions: petroleum coke – known as petcoke. Petcoke is the coal hiding in North America’s tar sands oil boom.

Petcoke is like coal, but dirtier. Petcoke looks and acts like coal, but it has even higher carbon emissions than already carbon-intensive coal.

On a per-unit of energy basis petcoke emits 5 to 10 percent more carbon dioxide than coal.

A ton of petcoke yields on average 53.6 percent more CO2 than a ton of coal.

Because it is considered a refinery byproduct, petcoke emissions are not included in most assessments of the climate impact of tar sands or conventional oil production and consumption. Thus the climate impact of oil production is being consistently undercounted.

Petcoke in the tar sands is turning American refineries into coal factories.

There is 24 percent more CO2 embedded in a barrel of tar sands bitumen than in a barrel of light oil.

15 to 30 percent of a barrel of tar sands bitumen can end up as petcoke, depending on the upgrading and refining process used.

Of 134 operating U.S. refineries in 2012, 59 are equipped to produce petcoke.

U.S. refineries produced over 61.5 million tons of petcoke in 2011 – enough to fuel 50 average U.S. coal plants each year.

In 2011, over 60 percent of U.S petcoke production was exported.

Keystone XL will fuel five coal plants and thus emit 13% more CO2 than the U.S. State Department has previously considered.

Nine of the refineries close to the southern terminus of Keystone XL have nearly 30 percent of U.S. petcoke production capacity, over 50,000 tons a day.

The petcoke produced from the Keystone XL pipeline would fuel 5 coal plants and produce 16.6 million metric tons of CO2 each year.

These petcoke emissions have been excluded from State Department emissions estimates for the Keystone XL pipeline.

Including these emissions raises the total annual emissions of the pipeline by 13% above the State Department’s calculations.

Cheap petcoke helps the coal industry.

As a refinery byproduct, petcoke is “priced to move”, selling at roughly a 25 percent discount to conventional coal.

Rising petcoke production associated with tar sands and heavy oil production is helping to make coal fired power generation dirtier and cheaper – globally.

“PetKoch”: The largest global petcoke trader in the world is Florida based Oxbow Corporation, owned by William Koch – the brother of Charles and David Koch.

Oxbow Carbon has donated $4.25 million to GOP super PACs, making it the one of the largest corporate donors to super PACs.

Oxbow also spent over $1.3 million on lobbyists in 2012.

To date, the impacts of petcoke on the local and global environment have not been considered by regulatory bodies in assessing the impacts of the tar sands. Petcoke’s full impacts must be considered by the European Union in its debate on the Fuel Quality Directive, by the U.S. State Department in its consideration of the climate impacts of the Keystone XL pipeline, and by Canadian, American, and European governments in tar sands policies across the board.

Increasing petcoke use is a clear result of the increasing production of tar sands bitumen. Petcoke is a seldom discussed yet highly important aspect of the full impacts of tar sands production. Factored into the equation, petcoke puts another strong nail in the coffin of any rational argument for the further exploitation of the tar sands.